Is a Virus Behind the Bee Plague?

Scientists have identified a likely culprit underlying the massive and mysterious plague that has killed off tens of millions of bees in the United States over the past year. By sequencing the DNA of every microbe inhabiting the bees, researchers have pinpointed a novel virus strongly linked to infected hives. The findings could help beekeepers protect their colonies. The research also suggests an effective new method for identifying infectious pathogens, be they from bees or humans.

"This is a very significant finding," says Dewey Caron, an entomologist at the University of Delaware, in Maryland, who was not involved in the study. "It's not yet a smoking gun, but it really helps narrow the search."

Over the past year, tens of millions of bees have mysteriously vanished from their hives, amounting to a loss of 50 to 90 percent of U.S. colonies. While honeybee populations have sustained several major hits to their numbers over the past century, this particular plague is unique in that adult bees seem to disappear from their hives without a trace. Because honeybees pollinate hundreds of species of fruits, vegetables, and nuts--commercial beekeepers truck their hives across the country during flowering season to pollinate crops--that loss is a major agricultural concern.

They found that one particular virus, known as Israeli acute paralysis virus of bees, was found only in colonies that suffered significant losses. In a follow-up study of 51 bee colonies from across the country--30 diseased colonies and 21 healthy ones--all but one colony infected with Israeli acute paralysis virus also had colony collapse disorder. In other words, the virus could predict collapse 96 percent of the time. The findings are published today online in the journal Science.